England scrum-half Ben Youngs has aimed a volley at his forward pack in the wake of Saturday's victory over France at Twickenham, insisting that they need to sharpen up their support running.

While England are on course for a Grand Slam after overcoming the only other previously unbeaten side in this year's Six Nations 17-9, Youngs was not pleased with the work of his forwards and sent a 'rollicking' their way at half-time.

"A win against the French is priceless, especially against a very good French side that came here to dominate and bully us and they simply didn't do so," he said. "But some guys are disappointed with their personal performances, me included. We demand high standards.

"There were a lot of us frustrated at half-time and getting a bit angry with each other. I gave the forwards a bit of a rollicking. I was running into spaces and there were holes around me and no-one was running off me. It was a little frustrating because you think 'what the hell are you doing?'"

"It is pretty simple. If I run out and the bloke comes to tackle there is usually a hole on my shoulder. We have to make sure our guys start reading that otherwise I will be getting even more frustrated."

Fly-half Toby Flood suggested that England's confidence may have taken a hit after a mixed performance but Youngs has insisted that they must take positives from the game after dealing with a physical French pack more effectively than they did South Africa's in November.

"Against the Springboks we got bullied and lost the game. This time we came out on top, which shows we are learning to deal with different game plans and styles," Youngs said."It shows we are moving in the right direction because this team wasn't happy with that performance. We know we have more to give, we should have closed the game out sooner and scored more points."

England now have a fortnight to prepare for Scotland's visit to Twickenham before they tackle Ireland in Dublin on the final weekend of the Championship, but manager Martin Johnson refuses to contemplate a Grand Slam yet.

"No-one has mentioned those words in my presence. That's crazy. If you are trying to win anything, you concentrate on what you need to do to win games, otherwise you are setting yourself up for a fall," Johnson said.

Meanwhile, 20 players have been retained in the England squad for a training camp in Oxford this week. Among them are Stade Francais duo Tom Palmer and James Haskell and Toulon fly-half Jonny Wilkinson, with their clubs all set for Top 14 action this weekend.